{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T00:20:46Z","timestamp":1760228446392,"version":"build-2065373602"},"reference-count":50,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2022,5,13]],"date-time":"2022-05-13T00:00:00Z","timestamp":1652400000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100000865","name":"Bill and Melinda Gates Foundation","doi-asserted-by":"publisher","award":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"],"award-info":[{"award-number":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"]}],"id":[{"id":"10.13039\/100000865","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"],"award-info":[{"award-number":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Outstanding Young Scholars Funding","award":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"],"award-info":[{"award-number":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"]}]},{"name":"Xi\u2019an Jiaotong University Basic Research and Profession","award":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"],"award-info":[{"award-number":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"]}]},{"name":"Xi\u2019an Jiaotong University Young Talent Support","award":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"],"award-info":[{"award-number":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"]}]},{"DOI":"10.13039\/501100002858","name":"China Postdoctoral Science Foundation","doi-asserted-by":"publisher","award":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"],"award-info":[{"award-number":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"]}],"id":[{"id":"10.13039\/501100002858","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Young Talent Support Program of Shaanxi University Association for Science and Technology","award":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"],"award-info":[{"award-number":["INV-006104","81950410639","12171387","3111500001","xtr022019003","xzy032020032","YX6J004","2018M631134","2020T130095ZX","20210307"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>It is still uncertain how the epidemic characteristics of COVID-19 in its early phase and subsequent waves contributed to the pre-delta epidemic size in the United States. We identified the early and subsequent characteristics of the COVID-19 epidemic and the correlation between these characteristics and the pre-delta epidemic size. Most (96.1% (49\/51)) of the states entered a fast-growing phase before the accumulative number of cases reached (30). The days required for the number of confirmed cases to increase from 30 to 100 was 5.6 (5.1\u20136.1) days. As of 31 March 2021, all 51 states experienced at least 2 waves of COVID-19 outbreaks, 23.5% (12\/51) experienced 3 waves, and 15.7% (8\/51) experienced 4 waves, the epidemic size of COVID-19 was 19,275\u20133,669,048 cases across the states. The pre-delta epidemic size was significantly correlated with the duration from 30 to 100 cases (p = 0.003, r = \u22120.405), the growth rate of the fast-growing phase (p = 0.012, r = 0.351), and the peak cases in the subsequent waves (K1 (p &lt; 0.001, r = 0.794), K2 (p &lt; 0.001, r = 0.595), K3 (p &lt; 0.001, r = 0.977), and K4 (p = 0.002, r = 0.905)). We observed that both early and subsequent epidemic characteristics contribute to the pre-delta epidemic size of COVID-19. This identification is important to the prediction of the emerging viral infectious diseases in the primary stage.<\/jats:p>","DOI":"10.3390\/pathogens11050576","type":"journal-article","created":{"date-parts":[[2022,5,13]],"date-time":"2022-05-13T08:37:02Z","timestamp":1652431022000},"page":"576","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["What Is the Impact of Early and Subsequent Epidemic Characteristics on the Pre-delta COVID-19 Epidemic Size in the United States?"],"prefix":"10.3390","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0277-9364","authenticated-orcid":false,"given":"Hao","family":"Lai","sequence":"first","affiliation":[{"name":"China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi\u2019an Jiaotong University Health Science Center, Xi\u2019an 710061, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yusha","family":"Tao","sequence":"additional","affiliation":[{"name":"SESH (Social Entrepreneurship to Spur Health) Global, University of North Carolina at Chapel Hill Project-China, Guangzhou 510095, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mingwang","family":"Shen","sequence":"additional","affiliation":[{"name":"China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi\u2019an Jiaotong University Health Science Center, Xi\u2019an 710061, China"},{"name":"Key Laboratory for Disease Prevention and Control and Health Promotion of Shaanxi Province, Xi\u2019an 710061, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Rui","family":"Li","sequence":"additional","affiliation":[{"name":"China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi\u2019an Jiaotong University Health Science Center, Xi\u2019an 710061, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Maosheng","family":"Zou","sequence":"additional","affiliation":[{"name":"China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi\u2019an Jiaotong University Health Science Center, Xi\u2019an 710061, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Leilei","family":"Zhang","sequence":"additional","affiliation":[{"name":"China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi\u2019an Jiaotong University Health Science Center, Xi\u2019an 710061, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2343-084X","authenticated-orcid":false,"given":"Lei","family":"Zhang","sequence":"additional","affiliation":[{"name":"China-Australia Joint Research Center for Infectious Diseases, School of Public Health, Xi\u2019an Jiaotong University Health Science Center, Xi\u2019an 710061, China"},{"name":"Artificial Intelligence and Modelling in Epidemiology Program, Melbourne Sexual Health Centre, Alfred Health, Melbourne, VIC 3053, Australia"},{"name":"Central Clinical School, Faculty of Medicine, Monash University, Melbourne, VIC 3800, Australia"},{"name":"Department of Epidemiology and Biostatistics, College of Public Health, Zhengzhou University, Zhengzhou 450001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,13]]},"reference":[{"key":"ref_1","first-page":"157","article-title":"WHO Declares COVID-19 a Pandemic","volume":"91","author":"Cucinotta","year":"2020","journal-title":"Acta Biomed."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1080\/22221751.2021.1898291","article-title":"Lessons learned 1 year after SARS-CoV-2 emergence leading to COVID-19 pandemic","volume":"10","author":"To","year":"2021","journal-title":"Emerg. Microbes Infect."},{"key":"ref_3","unstructured":"(2021, March 31). Coronavirus Resource Center of Johns Hopkins University & Medicine. Available online: https:\/\/coronavirus.jhu.edu\/."},{"key":"ref_4","unstructured":"(2021, April 05). Coronavirus in the U.S.: Latest Map and Case Count. Available online: https:\/\/www.nytimes.com\/interactive\/2021\/us\/covid-cases.html."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"929","DOI":"10.1056\/NEJMoa2001191","article-title":"First Case of 2019 Novel Coronavirus in the United States","volume":"382","author":"Holshue","year":"2020","journal-title":"N. Engl. J. Med."},{"key":"ref_6","unstructured":"(2021, May 16). US Coronavirus Vaccine Tracker. Available online: https:\/\/usafacts.org\/visualizations\/covid-vaccine-tracker-states\/."},{"key":"ref_7","unstructured":"(2021, May 08). Viral Variant Proportions in the United States, Available online: https:\/\/covid.cdc.gov\/covid-data-tracker\/#variant-proportions."},{"key":"ref_8","unstructured":"(2021, May 30). What Doctors Wish Patients Knew about the Dangerous Delta Variant. Available online: https:\/\/www.ama-assn.org\/delivering-care\/public-health\/what-doctors-wish-patients-knew-about-dangerous-delta-variant."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"103","DOI":"10.12688\/wellcomeopenres.15986.1","article-title":"Second waves, social distancing, and the spread of COVID-19 across the USA","volume":"5","author":"Friston","year":"2020","journal-title":"Wellcome Open Res."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"579559","DOI":"10.3389\/fpubh.2020.579559","article-title":"Early COVID-19 Interventions Failed to Replicate 1918 St. Louis vs. Philadelphia Outcomes in the United States","volume":"8","author":"Jalali","year":"2020","journal-title":"Front. Public Health"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"e20912","DOI":"10.2196\/20912","article-title":"Multiple Epidemic Wave Model of the COVID-19 Pandemic: Modeling Study","volume":"22","author":"Kaxiras","year":"2020","journal-title":"J. Med. Internet Res."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Hazem, Y., Natarajan, S., and Berikaa, E.R. (medRxiv, 2020). Hasty Reduction of COVID-19 Lockdown Measures Leads to the Second Wave of Infection, medRxiv, preprint.","DOI":"10.1101\/2020.05.23.20111526"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"e32","DOI":"10.2105\/AJPH.2013.301704","article-title":"Unraveling R0: Considerations for public health applications","volume":"104","author":"Ridenhour","year":"2014","journal-title":"Am. J. Public Health"},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Holme, P., and Masuda, N. (2015). The Basic Reproduction Number as a Predictor for Epidemic Outbreaks in Temporal Networks. PLoS ONE, 10.","DOI":"10.1371\/journal.pone.0120567"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"219","DOI":"10.1016\/j.ijid.2020.05.122","article-title":"Early characteristics of the COVID-19 outbreak predict the subsequent epidemic scope","volume":"97","author":"Zhang","year":"2020","journal-title":"Int. J. Infect. Dis."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"2703","DOI":"10.1007\/s10489-020-01942-7","article-title":"Forecasting COVID-19 outbreak progression using hybrid polynomial-Bayesian ridge regression model","volume":"51","author":"Saqib","year":"2021","journal-title":"Appl. Intell."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"110058","DOI":"10.1016\/j.chaos.2020.110058","article-title":"Prediction of epidemic trends in COVID-19 with logistic model and machine learning technics","volume":"139","author":"Wang","year":"2020","journal-title":"Chaos Solitons Fractals"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"33","DOI":"10.1080\/09720502.2020.1833447","article-title":"Prediction of Covid-19 trends in Europe using generalized regression neural network optimized by flower pollination algorithm","volume":"24","author":"Gupta","year":"2020","journal-title":"J. Interdiscip. Math."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"e19115","DOI":"10.2196\/19115","article-title":"Prediction of the COVID-19 Pandemic for the Top 15 Affected Countries: Advanced Autoregressive Integrated Moving Average (ARIMA) Model","volume":"6","author":"Singh","year":"2020","journal-title":"JMIR Public Health Surveill."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"17","DOI":"10.1016\/j.puhe.2020.12.018","article-title":"Evaluation of work resumption strategies after COVID-19 reopening in the Chinese city of Shenzhen: A mathematical modeling study","volume":"193","author":"Bai","year":"2021","journal-title":"Public Health"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"503","DOI":"10.1016\/j.ijid.2020.05.019","article-title":"Assessing the effects of metropolitan-wide quarantine on the spread of COVID-19 in public space and households","volume":"96","author":"Shen","year":"2020","journal-title":"Int. J. Infect. Dis."},{"key":"ref_22","first-page":"100114","article-title":"Mass testing-An underexplored strategy for COVID-19 control","volume":"2","author":"Shen","year":"2021","journal-title":"Innovation"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2295","DOI":"10.1016\/j.vaccine.2021.02.056","article-title":"Projected COVID-19 epidemic in the United States in the context of the effectiveness of a potential vaccine and implications for social distancing and face mask use","volume":"39","author":"Shen","year":"2021","journal-title":"Vaccine"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"197","DOI":"10.1007\/s11524-021-00517-2","article-title":"Effects of New York\u2019s Executive Order on Face Mask Use on COVID-19 Infections and Mortality: A Modeling Study","volume":"98","author":"Shen","year":"2021","journal-title":"J. Urban Health"},{"key":"ref_25","first-page":"100006","article-title":"What Is Required to Prevent a Second Major Outbreak of SARS-CoV-2 upon Lifting Quarantine in Wuhan City, China","volume":"1","author":"Zhang","year":"2020","journal-title":"Innovation"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Zhang, L., Tao, Y., Shen, M., Fairley, C.K., and Guo, Y. (2020). Can self-imposed prevention measures mitigate the COVID-19 epidemic?. PLoS Med., 17.","DOI":"10.1371\/journal.pmed.1003240"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"643","DOI":"10.1093\/cid\/ciaa934","article-title":"Spatiotemporal Characteristics of the COVID-19 Epidemic in the United States","volume":"72","author":"Wang","year":"2021","journal-title":"Clin. Infect. Dis."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1237","DOI":"10.1377\/hlthaff.2020.00608","article-title":"Strong Social Distancing Measures In The United States Reduced The COVID-19 Growth Rate","volume":"39","author":"Courtemanche","year":"2020","journal-title":"Health Aff."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"167","DOI":"10.1057\/s41271-020-00257-8","article-title":"Application of state law in the public health emergency response to COVID-19: An example from Delaware in the United States","volume":"42","author":"Goldstein","year":"2020","journal-title":"J. Public Health Policy"},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Gu, T., Mack, J.A., Salvatore, M., Sankar, S.P., Valley, T.S., Singh, K., Nallamothu, B.K., Kheterpal, S., Lisabeth, L., and Fritsche, L.G. (MedRxiv, 2020). COVID-19 outcomes, risk factors and associations by race: A comprehensive analysis using electronic health records data in Michigan Medicine, MedRxiv, preprint.","DOI":"10.1101\/2020.06.16.20133140"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"e2011102","DOI":"10.1001\/jamanetworkopen.2020.11102","article-title":"Comparison of Estimated Rates of Coronavirus Disease 2019 (COVID-19) in Border Counties in Iowa Without a Stay-at-Home Order and Border Counties in Illinois With a Stay-at-Home Order","volume":"3","author":"Lyu","year":"2020","journal-title":"JAMA Netw. Open"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Ram\u00edrez, I.J., and Lee, J. (2020). COVID-19 Emergence and Social and Health Determinants in Colorado: A Rapid Spatial Analysis. Int. J. Environ. Res. Public Health, 17.","DOI":"10.3390\/ijerph17113856"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"e2019284118","DOI":"10.1073\/pnas.2019284118","article-title":"Temperature and population density influence SARS-CoV-2 transmission in the absence of nonpharmaceutical interventions","volume":"118","author":"Smith","year":"2021","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"433","DOI":"10.1111\/jrh.12476","article-title":"Spatial Disparities in Coronavirus Incidence and Mortality in the United States: An Ecological Analysis as of May 2020","volume":"36","author":"Zhang","year":"2020","journal-title":"J. Rural. Health"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"020506","DOI":"10.7189\/jogh.10.020506","article-title":"Early epidemiological indicators, outcomes, and interventions of COVID-19 pandemic: A systematic review","volume":"10","author":"Patel","year":"2020","journal-title":"J. Glob. Health"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"n137","DOI":"10.1136\/bmj.n137","article-title":"Pandemic fatigue? How adherence to covid-19 regulations has been misrepresented and why it matters","volume":"372","author":"Reicher","year":"2021","journal-title":"BMJ"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1016\/j.pulmoe.2020.05.015","article-title":"Evaluating the massive underreporting and undertesting of COVID-19 cases in multiple global epicenters","volume":"27","author":"Lau","year":"2021","journal-title":"Pulmonology"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"3602","DOI":"10.1038\/s41467-021-23866-7","article-title":"Role of meteorological factors in the transmission of SARS-CoV-2 in the United States","volume":"12","author":"Ma","year":"2021","journal-title":"Nat. Commun."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"655","DOI":"10.1038\/s43588-021-00136-6","article-title":"Climatic signatures in the different COVID-19 pandemic waves across both hemispheres","volume":"1","author":"Fontal","year":"2021","journal-title":"Nat. Comput. Sci."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"279","DOI":"10.1093\/ageing\/afaa274","article-title":"Efficacy and safety of COVID-19 vaccines in older people","volume":"50","author":"Soiza","year":"2021","journal-title":"Age Ageing"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"28","DOI":"10.1038\/s41591-020-01202-8","article-title":"Immune determinants of COVID-19 disease presentation and severity","volume":"27","author":"Brodin","year":"2021","journal-title":"Nat. Med."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"782","DOI":"10.1001\/jama.2020.12839","article-title":"Pathophysiology, Transmission, Diagnosis, and Treatment of Coronavirus Disease 2019 (COVID-19): A Review","volume":"324","author":"Wiersinga","year":"2020","journal-title":"JAMA"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"1123","DOI":"10.1007\/s10654-020-00698-1","article-title":"Assessing the age specificity of infection fatality rates for COVID-19: Systematic review, meta-analysis, and public policy implications","volume":"35","author":"Levin","year":"2020","journal-title":"Eur. J. Epidemiol."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Wang, W., Shen, M., Tao, Y., Fairley, C.K., Zhong, Q., Li, Z., Chen, H., Ong, J.J., Zhang, D., and Zhang, K. (2021). Elevated glucose level leads to rapid COVID-19 progression and high fatality. BMC Pulm. Med., 21.","DOI":"10.1186\/s12890-021-01413-w"},{"key":"ref_45","first-page":"94","article-title":"Modeling COVID-19 scenarios for the United States","volume":"27","author":"Team","year":"2020","journal-title":"Nat. Med."},{"key":"ref_46","unstructured":"(2021, April 04). IHME\u2019s COVID-19 Projections. Available online: https:\/\/covid19.healthdata.org\/."},{"key":"ref_47","unstructured":"(2021, March 10). WorldPop Population Counts. Available online: https:\/\/www.worldpop.org\/project\/list\/."},{"key":"ref_48","unstructured":"(2018). Measuring performance on the Healthcare Access and Quality Index for 195 countries and territories and selected subnational locations: A systematic analysis from the Global Burden of Disease Study 2016. Lancet, 391, 2236\u20132271."},{"key":"ref_49","unstructured":"(2020, June 17). Joinpoint Software, Available online: https:\/\/surveillance.cancer.gov\/joinpoint\/."},{"key":"ref_50","unstructured":"(2021, March 19). COVID-19 Vaccines, Available online: https:\/\/www.fda.gov\/emergency-preparedness-and-response\/coronavirus-disease-2019-covid-19\/covid-19-vaccines."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/11\/5\/576\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:10:15Z","timestamp":1760137815000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/11\/5\/576"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,5,13]]},"references-count":50,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2022,5]]}},"alternative-id":["pathogens11050576"],"URL":"https:\/\/doi.org\/10.3390\/pathogens11050576","relation":{},"ISSN":["2076-0817"],"issn-type":[{"type":"electronic","value":"2076-0817"}],"subject":[],"published":{"date-parts":[[2022,5,13]]}}}